Idle at ~1100 DTC codes P0105 & P0300

[i3igmind]

Howdy folks,
new here, just bought a 97 QX4 with 187K. the car idle is at ~1100 rpm and the previous owner said this start to happen after he replaced the TPS. i followed the troubleshoot in the FSM and adjusted the TPS to 4.0V as per specs. but still no luck when i start the engine (sometime i have to crank it more than twice) the RPM just goes high and comes down to ~1100 and when i rev the engine it dies and sound like misfire. yesterday i bought a cheap OBD2 reader and the codes i got were P0105 and P0300, so i erased them and followed the procedure in the FMS to trouble diagnosis for DTC P0105.

with the engine running and idle @ ~1100 i disconnect the Absolute Pressure Sensor, nothing happen , no change in the engine noise or RPM? is this normal?
second , i took the multi-meter reading as recommended by the procedure , and every thing checked out!!!

am here today to seek you help , guide , assistance please to help me get this baby up and running. any little comment or suggestion might help me out as i am not that good with cars. i only fixed my other car 94 accord and replaced water pump and timing belt that was the biggest thing i ever did , so easy on me okay

P.s: previous owner said, the last time he changed the spark plugs was about 4 years ago. no tune ups other than changing oil.


thank you in advance

[Towncivilian]

Welcome to NICO.

P0300 indicates multiple cylinder misfire. Not knowing the maintenance history with your QX4, I would go ahead and change the spark plugs, distributor, and rotor. See this guide for details.

As for P0105, make sure none of the vacuum hoses connected to the sensor are clogged.

[i3igmind]

thank you

[i3igmind]

So i changed the spare plugs and dist. cab and replaced few vacuum hoses. checked the absolute pressure sensor reading and all checked out! but still will no idle to 750 rpm.

i took it for a ride and of course the car died on me on the freeway. i had it towed to a shop and the told me it needs a whole new dist. i agreed to change it! no change in rpm. they found that the fan coupling is bad as well.

now they say it need a new Throttle body because there is an arm that is bent "see attached pic" note this is not my throttle body. i want to know what is the actuator or piston look like that has green residue ( circled with red in the picture)

can someone please shed some light as where to start with this? also can someone with similar car take a picture of their TB from different direction and post it here so i can compare it.

thank you in advance

[i3igmind]

So I did so search and what it look like is that part I had circled in red is the ELEMENT KIT-THERMO[part#16391U]

And that arm I was talking about, turns out to be the CAM-FAST IDLE [Part#16128U].

My question is this now: could this be the real cause of my high idle issue? Do I change these out or should I just change the whole TB chamber? Or should I start by sea foaming first?